This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-291905 filed Sep. 26, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a liquid crystal composition, a liquid crystal display and a method of manufacturing the liquid crystal display.
2. Description of the Related Art
At present, a general liquid crystal display is manufactured in the following procedure. First, an electrode and an alignment film are successively formed on each of a pair of glass substrates having switching elements, a color filter layer, and the like. Subsequently, these glass substrates are disposed at a constant distance so that the alignment films are disposed opposite to each other, peripheries of the glass substrates excluding a liquid crystal sealing port are fixed with an adhesive, and a liquid crystal cell is formed. Additionally, a gap between the glass substrates is maintained to be constant by spacers. Thereafter, the gap between the liquid crystal cell is filled with a liquid crystal composition to form a liquid crystal layer, and the liquid crystal sealing port is sealed with a sealing material so that the liquid crystal display is obtained.
For the liquid crystal display manufactured by this method, when the liquid crystal layer is contaminated with an impurity, a display property is largely influenced. However, the contamination with the impurity cannot be avoided in the conventional liquid crystal display. Therefore, the conventional liquid crystal display has a problem that display unevenness occurs and reliability is deteriorated.
According to a first aspect of the present invention, there is provided a liquid crystal display comprising a first substrate, a second substrate facing the first substrate, and a liquid crystal layer intervening between the first and second substrates and containing liquid crystal substances different from each other, a sum of values each calculated from a formula:
Xxcex1(RTlogPxcex1+HExcex1) 
for all the liquid crystal substances in the liquid crystal layer being 32 kJ/mol or higher, wherein Xxcex1 denotes a molar fraction of a component xcex1 in the liquid crystal layer, Pxcex1 denotes a distribution ratio of the component xcex1 between an aqueous phase and a 1-octanol phase, HExcex1 denotes a hydration energy for 1 mol of the component xcex1, R denotes a gas constant of 8.3 J/Kxc2x7mol, and T denotes a temperature of 300 K.
According to a second aspect of the present invention, there is provided a method of manufacturing a liquid crystal display, the display comprising a pair of substrates and a liquid crystal layer intervening between the substrates and containing liquid crystal substances different from each other, comprising determining a composition of the liquid crystal layer based on a sum of values each calculated from a formula:
Xxcex1(RTlogPxcex1+HExcex1) 
for all the liquid crystal substances in the liquid crystal layer, wherein Xxcex1 denotes a molar fraction of a component xcex1 in the liquid crystal layer, Pxcex1 denotes a distribution ratio of the component xcex1, HExcex1 denotes a hydration energy for 1 mol of the component xcex1, R denotes a gas constant, and T denotes a temperature, and forming a structure comprising the liquid crystal layer intervening between the substrates and having the composition determined.
According to a third aspect of the present invention, there is provided a liquid crystal composition comprising liquid crystal substances different from each other, a sum of values each calculated from a formula:
Xxcex1(RTlogPxcex1+HExcex1) 
for all the liquid crystal substances being 32 kJ/mol or higher, wherein Xxcex1 denotes a molar fraction of one component xcex1 of the liquid crystal substances in the composition, Pxcex1 denotes a distribution ratio of the component xcex1 between an aqueous phase and a 1-octanol phase, HExcex1 denotes a hydration energy for 1 mol of the component xcex1, R denotes a gas constant of 8.3 J/Kxc2x7mol, and T denotes a temperature of 300 K.